The Army Corps of Engineers plans to be completely finished cleaning the AU-owned property at 4825 Glenbrook Rd. NW by late 2011, Spring Valley project manager Dan Noble announced at Tuesday's Resident Advisory Board meeting.
The Corps will begin writing a Remedial Investigation/Feasibility Study report on the property. The study will be a comprehensive review of all of the data collected from 4825 Glenbrook Rd. NW and will propose several different methods for “the final clean-up” of the property, Noble said at the meeting.
“The entire process will take nine to 12 months,” Noble said.
The property on Glenbrook Road was the president’s house until the 1980s, when it was moved down the street, The Eagle previously reported. AU continues to own both properties.
The Corps has been excavating a World War I-era chemical munitions burial pit, known as Pit 3, beneath the property since 2007.
Work was halted in March when workers discovered several jugs containing arsenic trichloride, a toxic gas found in chemical munitions.
In July, the Corps told residents that the house at 4825 Glenbrook Rd. NW was probably built on top of a layer of rock, according to the Northwest Current. However, when investigators began taking soil samples from the basement in August they discovered that there is as much as 10 feet of topsoil beneath the house. This means that there could be significantly more chemicals under the house than previously thought, according to Noble.
Noble told the RAB that the Corps considered restarting the clean-up, but there are too many “technical difficulties” at the site that need to be solved before work can begin again. These difficulties include how the Corps can effectively test for and disperse arsenic trichloride.
Arsenic trichloride is a chemical that is rarely used and “there is not a set of numbers for arsenic trichloride to determine what level is and isn’t safe,” Noble said.
The current air filtration system at 4825 Glenbrook Rd. NW has not been tested on the gas. Arsenic trichloride is a highly reactive gas that forms hydrochloric acid when exposed to oxygen. The Corps is unsure whether to test for arsenic trichloride or hydrochloric acid, Noble said Tuesday.
The Corps will release the Remedial Investigation/Feasibility Study to the public in December and consider comments from community members in selecting a cleanup plan. The plan is scheduled to be completed by June 2011.
mellmauer@theeagleonline.com
